Improvement in machines for rounding the corners of slate-frames



A. STRUH. Machine for Rounding the Corners of Slat-Frames.

N0,]62,505 Patented.April27,1875.

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UNITED STATES PATENT OrFIa.

ABRAHAM STROH, OF MAUOH CHUNK, PENNSYLVANIA.

IMPROVEMENT IN MACHINES FOR ROUNDING THE CORNERS 0F SLATE-FRAMES.

Specification f rming part of Letters Patent No. 162,505, dated April 27, 1875; application filed March 18, 1875.

To all whom it may concern Be it known that I, ABRAHAM STRoH, of Mauch Chunk, in the county of Carbon, State of Pennsylvania, have invented certain Improvements in Machines for Rounding the Corners of Slate-Frames, of which the following is a specification My invention relates to machines for rounding the corners of slates, such as are commonly used in schools; and the nature thereof consists in a segmental bed-plate, and having one or more groves made upon the lines of circles with a common center, and a vibratory or laterally-moving plate, with ridges or projecting rings formed upon the under side thereof, so that when the vibrating plate is placed in position upon the bed-plate the said rings fit in the grooves, and thus the movement of the upper plate is controlled and directed, as here inafter shown and described.

In the accompanying drawing, which illustrates my invention andforms a part of the specification herein, Figure l is a plan of my improved machine. Fig. 2 represents a verical section on the line a: ocof Fig. 1. Fig. 3 represents a plan of the under side of the vibratory plate.

In the drawing referred to, A designates the bed-plate, conveniently constructed some- What circular in form, and having at the front side the semicircular opening 0. One or more grooves, a, following the lines of circles, are formed in the said plate A, and the raised edge or shoulder 11 is formed at the rear. Apertures are also made in the bedplate suitable for the purpose of attachment to a table or other foundation.

The vibratory plate, indicated by letter B, and of the form shown, has one or more ridges or projecting rings formed on the under side thereof, the said rings 0 corresponding in shape and position with the grooves a in the bed-plate. The movable plate 13 is also provided with the apertures d, the same being made oblong and rabbeted on the under side, as shown, so as to hold the heads of the screwbolt 8, by which, with the nuts thereon, the adjustable guides E are clamped to the said plate B, as shown in Fig. 1. The guides E are placed in position at right angles to each other, leaving a space for the corner of a slate to pass between their inward extremities. The said guides are readily attached or detached by means of the nuts and screw-bolts 0, while the oblong apertures (I allow them to be adjustable to slates of various sizes.

In operation, the vibratory plate B is placed upon the bed-plate A, so that the outer edge of the former extends to the shoulder b, and the rings 0 set in the grooves 60 of the bed-plate. The slate is placed upon the plate B, so that it extends corner-wise toward the revolving knife or cutting-tool within the opening 0. The guides are adjusted to the slate, and the plate B, holding the latter, is then moved, the direction of its movement being controlled by the grooves a and the rings 0, While the corner of the slate is rounded by the action of the cutting-tool against it.

Having described my invention, I claim- The bed-plate A, provided with one or more grooves, a, and shoulder b, in combination with the plate B, provided with one or more rings, 0, constructed to operate as shown.

In witness whereof, I have subscribed my name hereto in the presence of two witnesses.

ABRAHAM STROH.

Witnesses:

W ILLIAM BUTLER, WM. G. FREYMAN. 

